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10.30.2011

Astronomers have discovered three new planets orbiting giant, dying stars. One of the stars also has a mystery object in orbit. The new data provides information about the evolution of extrasolar planetary systems.

The Sun as a red Giant.

Three planets -- each orbiting its own giant, dying star -- have been discovered by an international research team led by a Penn State University astronomer. Using the Hobby-Eberly Telescope, astronomers observed the planets' parent stars -- called HD 240237, BD +48 738, and HD 96127 -- tens of light years away from our solar system.

10.23.2011

According to Germany's space agency (the DLR), ROSAT re-entered Earth's atmosphere on Oct. 23rd sometime between 1:45 UT and 2:15 UT. So far, no credible sightings of the fireball have been reported, and officials don't know how much debris might have reached the ground

10.20.2011

The first direct image of a planet in the process of forming around its star has been captured by astronomers who combined the power of the 10-meter Keck telescopes with a bit of optical sleight of hand.

Left: The transitional disk around the star LkCa 15. All of the light at this wavelength is emitted by cold dust in the disk. the hole in the center indicates an inner gap with radius of about 55 times the distance from the Earth to the Sun. Right: An expanded view of the central part of the cleared region, showing a composite of two reconstructed images (blue: 2.1 microns, from November 2010; red: 3.7 microns) for LkCa 15. The location of the central star is also marked. Credit: Kraus & Ireland 2011

What astronomers are calling LkCa 15 b, looks like a hot “protoplanet” surrounded by a swath of cooler dust and gas, which is falling into the still-forming planet. Images have revealed that the forming planet sits inside a wide gap between the young parent star and an outer disk of dust.

10.19.2011

This artist's conception illustrates a storm of comets around a star near our own, called Eta Corvi. Image credit: NASA/JPL-Caltech

NASA's Spitzer Space Telescope has detected signs of icy bodies raining down in an alien solar system. The downpour resembles our own solar system several billion years ago during a period known as the "Late Heavy Bombardment," which may have brought water and other life-forming ingredients to Earth.

During this epoch, comets and other frosty objects that were flung from the outer solar system pummeled the inner planets. The barrage scarred our moon and produced large amounts of dust.

NASA's Fermi team recently released the second catalog of gamma-ray sources detected by their satellite's Large Area Telescope (LAT). Of the 1873 sources found, nearly 600 are complete mysteries. No one knows what they are. "Fermi sees gamma rays coming from directions in the sky where there are no obvious objects likely to produce gamma rays," says David Thompson, Fermi Deputy Project Scientist from Goddard Space Flight Center.

An all-sky map of gamma-ray emissions made by the Fermi Space Telescope. Hundreds of the sources in the map are complete mysteries.

Gamma rays are by their very nature heralds of great energy and violence. They are a super-energetic form of light produced by sources such as black holes and massive exploding stars. Gamma-rays are so energetic that ordinary lenses and mirrors do not work. As a result, gamma-ray telescopes can't always get a sharp enough focus to determine exactly where the sources are.

10.11.2011

ESA’s Venus Express spacecraft has discovered an ozone layer high in the atmosphere of Venus. Comparing its properties with those of the equivalent layers on Earth and Mars will help astronomers refine their searches for life on other planets. The results were presented at the Joint Meeting of the European Planetary Science Congress and the American Astronomical Society’s Division for Planetary Sciences.

Venus Express made the discovery while watching stars seen right at the edge of the planet set through its atmosphere. Its SPICAV instrument analyzed the starlight, looking for the characteristic fingerprints of gases in the atmosphere as they absorbed light at specific wavelengths.

The left image shows the star HR 8799 as seen by Hubble's Near Infrared Camera and Multi-Object Spectrometer (NICMOS) in 1998. The center image shows recent processing of the NICMOS data with newer, sophisticated software. The processing removes most of the scattered starlight to reveal three planets orbiting HR 8799. Based on the reanalysis of NICMOS data and ground-based observations, the illustration on the right shows the positions of the star and the orbits of its four known planets. (Credit: NASA; ESA; STScI, R. Soummer)Click on image for more detailed caption

In a painstaking re-analysis of Hubble Space Telescope images from 1998, astronomers have found visual evidence for two extrasolar planets that went undetected back then.

Finding these hidden gems in the Hubble archive gives astronomers an invaluable time machine for comparing much earlier planet orbital motion data to more recent observations. It also demonstrates a novel approach for planet hunting in archival Hubble data.

10.05.2011

Astronomers have discovered a multi-planet system containing a super-Earth and two Neptune-sized planets. Uniquely, the planets orbit in resonance with each other and around a star similar to the Sun.

The top graphic shows the orbits of the three known planets orbiting Kepler-18 as compared to Mercury's orbit around the Sun. The bottom graphic shows the relative sizes of the Kepler-18 and its known planets to the Sun and Earth. Credit: Tim Jones/McDonald Obs./UT-Austin

A team of researchers led by Bill Cochran of The University of Texas at Austin has used NASA’s Kepler spacecraft to discover an unusual multiple-planet system containing a super-Earth and two Neptune-sized planets orbiting in resonance with each other. They announced the find in Nantes, France, at a joint meeting of the American Astronomical Society’s Division of Planetary Science and the European Planetary Science Conference. The research will be published in a special Kepler issue of The Astrophysical Journal Supplement Series in November.

10.03.2011

Planetary scientists at Brown University and participating institutions have discovered vast, smooth plains around Mercury’s north pole that were created by volcanic activity more than 3.5 billion years ago. The lava flows were epic: They filled craters more than a mile deep and cover 6 percent of Mercury’s surface, an area that would cover nearly 60 percent of the continental United States, the scientists write in the journal Science.

Giant lava flows on MercuryLava flows on Mercury more than 3.5 billion years ago — a mile deep in places — would have covered nearly 60 percent of the continental United States. The discovery was made by data returned from NASA’s MESSENGER mission to Mercury.

Ever since the Mariner 10 mission in 1974 snapped the first pictures of Mercury, planetary scientists have been intrigued by smooth plains covering parts of the surface. Some suspected past volcanic activity, but there were no telltale signs like protruding volcanoes. Also, Mercury’s northern plains are the same brightness as its cratered highlands, yet different from volcanic deposits on the Moon, which are darker than the highlands.

Spectrum-R, developed under Radioastron project in the framework of Russian Federal Space Program, is intended to study the Universe. The aim of the mission is to use the space telescope to conduct interferometer observations in conjunction with the global ground radio telescope network in order to obtain images, coordinates, motions and evolution of angular structure of different radio emitting objects in the Universe.

Scientists also expect to obtain more information about pulsars and interstellar plasma, black holes and neutron stars in the Milky Way. The spacecraft's operational lifetime will be no less than five years.

On September 27, 2011, the first light from Cassiopeia A was detected with the space radio telescope Spektr-R of the Radioastron mission. The telescope scanned across the supernova remnant in two perpendicular directions. Signal in two bands of 92 and 18 cm (two circular polarization per band) was successfully detected in the total power mode. Enjoy the first light picture.

First observation of the space object, supernova remnant Cassiopeia A, by the space radio telescope Radioastron in a scanning mode.Copyright: ASC Lebedev